Major Democrat party donors have turned on Joe Biden following his disastrous performance in the first US presidential debate, with one adviser saying the only options now were that he “bows out or dies”.

Donors have urged Mr Biden to step aside, suggesting California’s Gavin Newsom and Michigan governor Gretchen Whitmer as potential replacements amid rising panic about the future of the campaign.

Mr Biden repeatedly struggled to express himself during the debate with Donald Trump, producing rambling and incoherent answers.

The high-profile Democrat donor, Mark Buell, raised the possibility of replacing Mr Biden following the debate, saying: “Do we have time to put somebody else in there?”

One adviser to major Democratic Party donors told Politico: “Our only hope is that he bows out, we have a brokered convention, or dies”.

Strategists working for at least three separate Democrats said they have received texts from party donors asking them if their candidate would step forward to replace Biden as the presidential nominee.

“Biden needs to drop out. No question about it,” one said, proposing a ticket led by Ms Whitmer and Wes Moore, the governor of Maryland.  

“This is terrible. Worse than I thought was possible. Everyone I’m speaking with thinks Biden should drop out,” one Democrat donor told NBC News.

One adviser told Politico that they had “taken no less than half a dozen key donors texting ‘disaster’ and [the] party needs to do something.”

Follow our afternoon coverage of the debate fallout here.